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.Dd $Mdocdate: May 28 2016 $
.Dt RCMDSH 3
.Os
.Sh NAME
.Nm rcmdsh
.Nd return a stream to a remote command without superuser
.Sh SYNOPSIS
.In unistd.h
.Ft int
.Fn rcmdsh "char **ahost" "int inport" "const char *locuser" "const char *remuser" "const char *cmd" "char *rshprog"
.Sh DESCRIPTION
The
.Fn rcmdsh
function is used by normal users to execute a command on a remote machine
using an authentication scheme based on reserved port numbers using
.Xr ssh 1
or the value of
.Fa rshprog
(if non-null).
.Fa rshprog
may be a fully-qualified path, a non-qualified command, or a command containing
space-separated command line arguments.
.Pp
The
.Fn rcmdsh
function looks up the host
.Fa *ahost
using
.Xr getaddrinfo 3
and, if the host exists,
.Fa *ahost
is set to the canonical name of the host.
A connection is then established to
a server residing at the well-known Internet port
.Li shell/tcp
(or whatever port is used by
.Fa rshprog ) .
The parameter
.Fa inport
is ignored; it is only included to provide an interface similar to
.Xr rcmd 3 .
.Pp
If the connection succeeds, a socket in the
.Ux Ns -domain
of type
.Dv SOCK_STREAM
is returned to the caller, and given to the remote
command as stdin and stdout, and stderr.
.Sh DIAGNOSTICS
The
.Fn rcmdsh
function returns a valid socket descriptor on success.
It returns \-1 on error and prints a diagnostic message on the standard error.
.Sh SEE ALSO
.Xr ssh 1 ,
.Xr socketpair 2 ,
.Xr rcmd 3
.Sh HISTORY
The
.Fn rcmdsh
function first appeared in
.Ox 2.0 .
.Sh BUGS
If
.Xr ssh 1
encounters an error, a file descriptor is still returned instead of \-1.
